pratt



(No Model.) N. W. PRATT.

PNEUMATIC CARTRIDGE.

No. 387,256. Patented Aug. '7, 1888.

I [NV/:NTOR. I

A TTORNEY.

UNITED STATES PATENT FFICE.

NAT. \V. PRATT, OF BROOKLYN, ASSIGNOR TO THE PNEUMATIC DYNAMITE GUNCOMPANY, OF NEW YORK, N. Y..

PNEUMATIC CARTRIDGE.

SPECIFICATION forming part of Letters Patent No. 387,256, dated August7, 1888. Application filed April 2, 1886. Renewed September 29, 1887.Serial No. 251,054. (No model.)

To all whom, it may concern:

Be it known that 1, NAT. W. PRATT, a citizen of the United States,residing at Brooklyn, in the county of Kingsand State of- New York, haveinvented a new and useful Improvement in Pressure-Cartridges, of whichthe following is a specification, reference being had to theaccompanying drawings, forming a part of the same, in which- Figure 1represents a longitudinal sectional side view of a cartridge embodyingmy invention arranged, together with a projectile, in a gun ready forfiring. Fig. 2 is a longitudinal sectional plan view of the cartridge,and showing a means of attaching the projectile to the cartridge; andFig. 3, an external view of the cartridge charged and sealed fortransportation.

To enable others to understand and practice my invention, I will firstproceed to describe a construction embodying the same, and subsequentlyto point out in the claims its novel characteristics.

In the drawings the essential parts and details of construction areindicated by corresponding letters of reference in the several figures.

A represents the shell of the cartridge; B, a rotating exhaust-valvelocated in its base; 0, a connected or contact pin for operating thevalve, said pin extending through the shell of the cartridge in positionto register with the firing-pin a, that passes through and pro- .jectsfrom the gun-barrel breech. The interior of the shell is fitted with avalve, E, for closing the outlet at its forward end. This valve E isattached to a valve-rod, D, which is connected to a piston, F, at itsopposite end, said piston being fitted-to reciprocate in a chamberedportion of theinterior of the shell adjacent to its base.

The exhaust-valve B is constructed with a recess that forms a passagethrough it when turned to register with the exhaust-port b, as indicatedby the arrow in Fig. 2.

The projectile is shown at H, and in Fig. 1 is represented disconnectedfrom the cartridge. In Fig. 2 the projectile is shown connected theretoby means of a sleeve or ferrule, i, into which the end of thecartridge-shell and the base of the projectile are placed, so that, if

desired, the cartridge and projectile may be passed into the guntogether.

In Fig. 3 the cartridge is shown ready for transportation, the forwardend having asealed cover or cap, h, and the openings at and near itsbase fitted with screw-plugsg g.

I have now referred to such essential parts and-details of constructionthat are necessary to the operation of the invention, which I will nowexplain.

The interior of the cartridge is charged with gas or air under highpressure through the port b and valve B, by means of any suitableconnected air compressing apparatus, the pressure being equalized onopposite sides of the piston F by means of an opening through or aroundits periphery, which is fitted with a cup-packing that will allow the'air to-pass in one direction. A central opening at K may be providedand fitted with a.v balanced check-valve opening from the forward side.The internal pressure closes the valve E, and when closed the piston Fis located at the position shown, and the valve Bis placed to close theport b, as shown in Fig. 1. The cartridge is now'charged and ready forfiring, and if it is to be transported a sealed cap, 72, is placed overits forward end, and screw-plugs g g inserted in the exhaust-port andover or in place of the pin 0, which will prevent any leakage or loss ofinternal pressure.

In firing the cartridge the valve B is opened by means of a hammeracting on the spring firing-pin a, which in turn forces the pin 0inwardly, as shown in Fig. 1. This opens the valve B and allows the airto escape from the back of the piston F and relieves the pressure fromthat side. The pressure on the opposite or forward side of the piston isheld by the cup-packing or by a check-valve, as suggested, and thepiston is instantly moved backward,

and by means of the connected valverod D a shell containing dynamite orother explosive, the valve E is provided with a conical extension orprolongation, e, which lifts with the valve and at first allows but aportion of the air to act, thus efl'ecting a gradual start in theprojectile and avoiding ashock that might communicate to and explode theprojectile when loaded with an explosive.

For the purpose of this application I have shown a means fol-operatingthe exhaust-valve B; but I do not wish to be confined to such specialdevices for the purpose, as it is obvious that the valve may be operatedby other firing mechanisms or by an outwardly-projecting hand-pieceforming an extension of the valve.

Having thus fully described my invention, what I claim, and desire tosecure by Letters Patent, is-

1. A cartridge containing air or gas under compression, provided with avalve-seat and valve, said valve having a conical projection extendingthrough the valve-seat to ell'ect a grad uall y-increasi n g dischargeof the contained air. 2. A cartridge containing air or gas undercompression,provided with a diseharge-valve, said valve being connectedto a. reciprocating piston which upon the exhaustion of air or gas fromthe chamber at its rear is retracted to operate said discharge-valve, asdescribed. 3. A cart-ridge containing air or gas under eon'lpression,having interior] y a piston-valve adapted to be held seated by thecontained air or gas, and a second "alve which governs the air orgaspassage leading to the chamber at the rear of said pistonvalve,whereby the pressure of the air or gas is relieved upon one side of saidpistonvalve to move it from its seat, substantially as described.

I N A'l. \V. PRATT. \Vitncsscs:

CHAS. W. Forums, A. O. RAWLINHS.

